PHILADELPHIA — Hillary Clinton marked her place in history on Thursday night by accepting the Democratic presidential nomination, fighting to shift perceptions that have dogged her for more than two decades on a global stage as first lady, U.S. senator and secretary of state.

Clinton, 68, becomes the first woman nominee of a major American party, a milestone not lost on her allies at the Democratic National Convention this week. Images of shattered glass ceilings and ringing proclamations of progress from civil rights icons and lawmakers who broke barriers of their own filled the four days leading to Clinton's address here.

"Tonight, we've reached a milestone in our nation's march toward a more perfect union. The first time that a major party has nominated a woman for president," Clinton said to a standing ovation. "Standing here as my mother's daughter, and my daughter's mother, I'm so happy this day has come. Happy for grandmothers and little girls and everyone in between. Happy for boys and men, too, because when any barrier falls in America, for anyone, it clears the way for everyone. When there are no ceilings, the sky's the limit."

She channeled the prevailing theme of optimism that the Democrats this week have tried to contrast with Republican billionaire Donald Trump's acceptance speech in Cleveland last week. She described a clear difference from Trump and the GOP on key issues, calling to protect undocumented immigrants from deportation, act on climate change and maintain women's health care institutions. She echoed Vice President Joe Biden in portraying the Democratic Party as the party of the middle class.

"So don't let anyone tell you that our country is weak. We're not. Don't let anyone tell you that we don't have what it takes. We do," she said. "And most of all, don't believe anyone who says, 'I alone can fix it.' Those were actually Donald Trump's words in Cleveland," Clinton said.

Saul Loeb | AFP | Getty Images

Democratic presidential nominee Hillary Clinton arrives on stage during the fourth and final night of the Democratic National Convention at Wells Fargo Center on July 28, 2016 in Philadelphia, Pennsylvania.

Clinton emerges from a contentious primary with Vermont Sen. Bernie Sanders and enters a tilt with Trump facing doubts across the political spectrum. The former secretary of state, U.S. senator and first lady's time as a household name leaves plenty of attack fodder for Republicans and Democrats alike.

After daughter Chelsea introduced her, Clinton took laps around the Wells Fargo Center stage, smiling and waving. Her speech barely started before some in the crowd began booing and chanting "never Hillary!" But quickly chants of "Hillary" and calls for quiet followed from Clinton supporters in the arena, who drowned out several interruptions throughout the speech.

Just this month, the Department of Justice announced it would not file criminal charges over Clinton's handling of classified information that FBI Director James Comey deemed "extremely careless." Energetic Sanders supporters were emboldened at the convention's start by WikiLeaks releasing emails that raised questions about Clinton bias within the Democratic Party.

Clinton thanked Sanders for mobilizing voters, and the senator clapped and smiled slightly in his seat at the mention.

"I want to thank Bernie Sanders. Bernie, your campaign inspired millions of Americans, particularly the young people who threw their hearts and souls into our primary. You've put economic and social justice issues front and center, where they belong. And to all of your supporters here and around the country: I want you to know, I've heard you. Your cause is our cause," Clinton said, prompting chants of "Bernie!"

Justin Sullivan | Getty Images

Democratic presidential nominee Hillary Clinton waves to the crowd on the fourth day of the Democratic National Convention at the Wells Fargo Center, July 28, 2016 in Philadelphia, Pennsylvania.

Perceptions of a cold, entrenched insider have tracked Clinton in an election marked by rising populism on both sides of the aisle. They have persisted even as it became apparent she would face Trump, a man who has never held public office and has drawn ire with remarks about immigrants and women.

Powerful surrogates for Clinton this week have tried to humanize her while describing Trump as woefully unprepared to lead the United States. Her husband, former President Bill Clinton, told rambling stories about the activist he fell in love with in the 1970s.

President Barack Obama, the Democrat who defeated Clinton in 2008 before naming her his top diplomat, described a tenacious woman who would capture the American values he has promoted for nearly eight years. Biden, drawing on his folksy appeal, said Trump "has no clue" about a middle class Clinton has known for decades.

"A man you can bait with a tweet is not a man you can trust with nuclear weapons."-Hillary Clinton on Donald Trump.

Clinton attacked Trump's business record and history of making products outside of the United States. To "make America great again," he would need to make products in the U.S. again, she said. She also warned about his temperament, experience and ability to handle diplomacy and terrorism, citing his tendency to respond to criticism on Twitter. "A man you can bait with a tweet is not a man you can trust with nuclear weapons," she said.

Clinton contended that "there is no other Donald Trump" than the bombastic candidate Americans have seen.